Treating water is understood as, besides filtration, also the measured dispensing of substances into the water. The dispensing of substances can also be combined with a filtration of the water.
Filtration cartridges are understood as, first, those which have a sievelike structure for mechanical filtration. Secondly, filtration cartridges are understood as also those which contain, besides a sievelike structure, at least one filtration medium, such as one in granulate form, which serves for chemical and/or mechanical removal and/or decreasing of organic and/or inorganic impurities. Such filtration cartridges thus enable a nonmechanical filtration, which can be combined with a mechanical filtration. These filtration cartridges are used for optimization of water, meaning by optimization a mechanical and/or nonmechanical filtration. This includes, e.g., the softening and deliming of drinking water.
The filtration can be pressure-operated, i.e., using excess pressure or partial vacuum, or it can be done by gravity.
WO 01/64312 discloses various embodiments of filtration cartridges that basically have a receptacle with filtration agents and connecting heads at the bottom and at the top. In a first embodiment, cylindrical connections are specified, which are inserted in the axial direction into correspondingly configured connecting elements. Inlet and outlet channels extend in the axial and, thus, the inserting direction.
A second embodiment shows connections bent at an angle, which allow the filtration cartridges to be pushed onto a correspondingly configured connecting element perpendicular to their lengthwise axis.
A third embodiment has a lower ball and socket joint head and an upper connecting head, which is bent at an angle, so that it can be inserted into the connecting element in a direction perpendicular to the lengthwise axis. By swinging the filtration cartridge about the ball and socket head, the filtration cartridge and the connecting element are brought together. The outlet channel likewise extends in the inserting direction. A modification of the upper connecting head calls for an outlet channel that extends in the lengthwise direction of the filtration cartridge.
What is common to all embodiments is two connecting heads, so that two inserting or connecting processes are also required when replacing the filtration cartridge, in order to connect the filtration cartridge properly. Furthermore, the ball and socket heads are costly and have sealing problems, since the ball and socket head also receives the inlet channel and the sealing elements can sometimes get damaged during the swinging movement of the filtration cartridge.
US 2006/0032202 specifies a filtration device with several filtration cartridges arranged next to each other, each having a single connecting head at the upper end. The connecting head contains both the inlet and the outlet channel. The filtration cartridge is inserted by its lower end into a swivel holder and then turned to join the connecting head to the connecting element.
Furthermore, filtration cartridges are known with a cylindrical connecting head, which are screwed by a turning movement into the connecting element.
U.S. Pat. No. 5,653,871 discloses a filtration device in which the inlet and the outlet channel are arranged opposite each other in the cylindrical connecting head. The sealing is done by O-rings, which are inserted into a groove made in the circumference of the cylindrical surface. For connecting heads which are made by the injection molding process, for example, the separation joints due to the molding dies used run through this groove, which favors leaks. Since the cylindrical holder of the connecting element is adapted by its internal cross section to the external cross section of the cylindrical connecting head of the filtration cartridge and a seal must be guaranteed by the O-rings, substantial frictional forces are required when inserting the filtration cartridge. Furthermore, the sealing elements may be subject to wear.
The same problems also occur with the device of US 2004/0211931 A1. The connecting head of the filtration cartridge consists of two sections, namely, a cylindrical section, which carries at least one O-ring seal, and a semicylindrical section, on which a beveled surface with outlet openings is arranged. The beveled surface serves as a cam surface for activating a valve arranged in the connecting element.